Ferromagnetic Sputtering Target with Less Particle Generation

Abstract

Provided is a nonmagnetic-material-dispersed sputtering target having a metal composition comprising 20 mol % or less of Cr and the balance of Co. The target has a structure including a phase (A) in which a nonmagnetic oxide material is dispersed in the basis metal, and a metal phase (B) containing 40 mol % or more of Co; the area proportion of grains of the nonmagnetic oxide material in the phase (A) is 50% or less; and when a minimum-area rectangle circumscribed to the phase (B) is assumed, the proportion of the circumscribed rectangle having a short side of 2 to 300 μm is 90% or more of all of the phases (B). The ferromagnetic sputtering target can suppress particle generation during sputtering and can improve leakage magnetic flux to allow stable electrical discharge with a magnetron sputtering apparatus.

1 . A nonmagnetic-material-dispersed sputtering target having a metal composition comprising 20 mol % or less of Cr and the balance of Co, wherein:
 the target structure includes a phase (A) in which a nonmagnetic oxide material is dispersed in a basis metal, and a metal phase (B) containing 40 mol % or more of Co;   the area proportion of grains of the nonmagnetic oxide material in the phase (A) is 50% or less; and   when a minimum-area rectangle circumscribed to the phase (B) is assumed, the aspect ratio of the circumscribed rectangle is in a range of 1:1 to 1:15 in all of the phases (B) and the proportion of the circumscribed rectangle having a short side of 2 to 300 μm is 90% or more of all of the phases (B).   
     
     
         2 . A nonmagnetic-material-dispersed sputtering target having a metal composition comprising 20 mol % or less of Cr, 5 mol % or more and 30 mol % or less of Pt, and the balance of Co, wherein:
 the target structure includes a phase (A) in which a nonmagnetic oxide material is dispersed in a basis metal, and a metal phase (B) containing 40 mol % or more of Co;   the area proportion of grains of the nonmagnetic oxide material in the phase (A) is 50% or less; and   when a minimum-area rectangle circumscribed to the metal phase (B) is assumed, the aspect ratio of the circumscribed rectangle is in a range of 1:1 to 1:15 in all of the phases (B) and the proportion of the circumscribed rectangle having a short side of 2 to 300 μm is 90% or more of all of the phases (B).   
     
     
         3 . A nonmagnetic-material-dispersed sputtering target having a metal composition comprising 5 mol % or more and 30 mol % or less 30 of Pt and the balance of Co, wherein:
 the target structure includes a phase (A) in which a nonmagnetic oxide material is dispersed in a basis metal, and a metal phase (B) containing 40 mol % or more of Co;   the area proportion of grains of the nonmagnetic oxide material in the phase (A) is 50% or less; and   when a minimum-area rectangle circumscribed to the phase (B) is assumed, the aspect ratio of the circumscribed rectangle is in a range of 1:1 to 1:15 in all of the phases (B) and the proportion of the circumscribed rectangle having a short side of 2 to 300 μm is 90% or more of all of the phases (B).   
     
     
         4 . The nonmagnetic-material-dispersed ferromagnetic sputtering target according to  claim 3 , wherein the area proportion of grains of the nonmagnetic oxide material in the phase (A) is 17% or more and 50% or less. 
     
     
         5 . The ferromagnetic sputtering target according to  claim 4 , wherein the basis metal further comprises at least one additional element selected from B, Ti, V, Mn, Zr, Nb, Ru, Mo, Ta and W in an amount of 0.5 mol % or more and 10 mol % or less, and the balance is Co. 
     
     
         6 . The ferromagnetic sputtering target according to  claim 3 , wherein the basis metal further comprises at least one additional element selected from B, Ti, V, Mn, Zr, Nb, Ru, Mo, Ta and W in an amount of 0.5 mol % or more and 10 mol % or less, and the balance is Co. 
     
     
         7 . The nonmagnetic-material-dispersed ferromagnetic sputtering target according to  claim 2 , wherein the area proportion of grains of the nonmagnetic oxide material in the phase (A) is 17% or more and 50% or less. 
     
     
         8 . The ferromagnetic sputtering target according to  claim 7 , wherein the basis metal further comprises at least one additional element selected from B, Ti, V, Mn, Zr, Nb, Ru, Mo, Ta and W in an amount of 0.5 mol % or more and 10 mol % or less, and the balance is Co. 
     
     
         9 . The ferromagnetic sputtering target according to  claim 2 , wherein the basis metal further comprises at least one additional element selected from B, Ti, V, Mn, Zr, Nb, Ru, Mo, Ta and W in an amount of 0.5 mol % or more and 10 mol % or less, and the balance is Co. 
     
     
         10 . The nonmagnetic-material-dispersed ferromagnetic sputtering target according to  claim 1 , wherein the area proportion of grains of the nonmagnetic oxide material in the phase (A) is 17% or more and 50% or less. 
     
     
         11 . The ferromagnetic sputtering target according to  claim 10 , wherein the basis metal further comprises at least one additional element selected from B, Ti, V, Mn, Zr, Nb, Ru, Mo, Ta and W in an amount of 0.5 mol % or more and 10 mol % or less, and the balance is Co. 
     
     
         12 . The ferromagnetic sputtering target according to  claim 1 , wherein the basis metal further comprises at least one additional element selected from B, Ti, V, Mn, Zr, Nb, Ru, Mo, Ta and W in an amount of 0.5 mol % or more and 10 mol % or less, and the balance is Co.